Car won't start unless I pour alttle gas in carb.

that's a tough one for sure! so it needs some fuel? carb fuel filter if so equipped,or flote not dropping letting fuel flow, bang on carb with something.not too hard now but maby flote will drop,or maybe the alcohol laden scrap gas sold anymore destroyed the diaphragm in the mechanical fuel pump

okay this carb has a thermal heat-riser and butterfly choke~ not only that has to squirt a bit of gas when the accelerator is depressed...this ole boy is called an "accelerator pump" and is at the bottom of the carb bowl...it has leather seals that go bad~ and wont juice the goose anymore...also there's a thermal link that positions the accelerator out of "kick down" to a high position for startup~

service your carburetor~ a weekend on the kitchen table with plastic bags and little chits of paper what correspond to the instruction sheet in that rebuild kit is a weekend project...with a case of soda~ https://www.google.com/#q=1983+Mercury+Cougar+carburetor+rebuild+kit&t bm=shop